Colored composition for electrowetting display, image display structure, and electrowetting display device

Abstract

A colored composition for use in electrowetting displays includes a non-polar solvent and a dipyrromethene dye having a solubility in n-hexane of 1% by mass or higher at 25° C. and 0.1 MPa. In a particular embodiment, an electrowetting display device that employs the colored composition exhibits increased responsiveness, and exhibits suppressed backflow at the time of image display.

What is claimed is: 
     
       1. A colored composition for use in electrowetting displays, the colored composition comprising:
 a dipyrromethene dye having a solubility in n-hexane of 1% by mass or higher at 25° C. and 0.1 MPa, the dipyrromethene dye being a compound represented by the following Formula (I-3): 
 
       
         
           
           
               
               
           
         
         wherein, in Formula (I-3), each of R 2 , R 3 , R 4 , and R 5  independently represents a hydrogen atom or a monovalent substituent; R 7  represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group, or a heterocyclic group; each of R 8  and R 9  independently represents an alkyl group, an alkenyl group, an aryl group, a heterocyclic group, an alkoxy group, an aryloxy group, an alkylamino group, an arylamino group, or a heterocyclic amino group; Ma represents a metal atom or a metal compound; each of X 3  and X 4  independently represents NRa (wherein Ra represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a heterocyclic group, an acyl group, an alkylsulfonyl group, or an arylsulfonyl group), a nitrogen atom, an oxygen atom, or a sulfur atom; each of Y 1  and Y 2  independently represents NRb (wherein Rb represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a heterocyclic group, an acyl group, an alkylsulfonyl group, or an arylsulfonyl group), a nitrogen atom, an oxygen atom, a sulfur atom, or a carbon atom; X 5  represents a group that can be bonded to Ma; “a” represents 1 or 2; R 8  and Y 1  may be linked to each other to form a 5-, 6-, or 7-membered ring; and R 9  and Y 2  may be linked to each other to form a 5-, 6-, or 7-membered ring; and 
         a non-polar solvent. 
       
     
     
       2. The colored composition according to  claim 1 , wherein at least one selected from the group consisting of R 2 , R 3 , R 4 , R 5 , R 8  and R 9  in Formula (I-3) represents a linear or branched alkyl group having from 1 to 20 carbon atoms. 
     
     
       3. The colored composition according to  claim 1 , wherein X 5  in Formula (I-3) represents a group that neutralizes an electric charge of Ma, the group containing a linear or branched alkyl group having from 1 to 20 carbon atoms. 
     
     
       4. The colored composition according to  claim 1 , wherein X 5  in Formula (I-3) represents a linear or branched alkyl ester group having from 1 to 20 carbon atoms. 
     
     
       5. An image display structure comprising:
 a hydrophobic insulating film layer having a hydrophobic surface; 
 an oil layer arranged so as to contact the hydrophobic surface and formed using a non-conductive oil comprising the colored composition according to  claim 1 ; and 
 a hydrophilic liquid layer arranged so as to contact the oil layer. 
 
     
     
       6. An electrowetting display device comprising a display unit, the display unit comprising:
 a first substrate, at least part of a surface of the first substrate being electrically conductive; 
 a second substrate disposed so as to face the electrically conductive surface of the first substrate; 
 a hydrophobic insulating film disposed on at least part of a surface of the first substrate at a side at which the electrically conductive surface is disposed; 
 a non-conductive oil disposed between the hydrophobic insulating film and the second substrate such that the non-conductive oil is movable on the hydrophobic insulating film, the non-conductive oil comprising a colored composition for use in electrowetting displays, and the colored composition comprising a non-polar solvent and a dipyrromethene dye having a solubility in n-hexane of 1% by mass or higher at 25° C. and 0.1 MPa; and 
 an electrically conductive hydrophilic liquid disposed between the hydrophobic insulating film and the second substrate such that the hydrophilic liquid contacts the non-conductive oil, 
 wherein an image is formed by changing a shape of an interface between the non-conductive oil and the hydrophilic liquid by the application of a voltage between the hydrophilic liquid and the electrically conductive surface of the first substrate, and 
 wherein the dipyrromethene dye is a compound represented by the following Formula (I-3): 
 
       
         
           
           
               
               
           
         
         wherein, in Formula (I-3), each of R 2 , R 3 , R 4 , and R 5  independently represents a hydrogen atom or a monovalent substituent; R 7  represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group, or a heterocyclic group; each of R 8  and R 9  independently represents an alkyl group, an alkenyl group, an aryl group, a heterocyclic group, an alkoxy group, an aryloxy group, an alkylamino group, an arylamino group, or a heterocyclic amino group; Ma represents a metal atom or a metal compound; each of X 3  and X 4  independently represents NRa (wherein Ra represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a heterocyclic group, an acyl group, an alkylsulfonyl group, or an arylsulfonyl group), a nitrogen atom, an oxygen atom, or a sulfur atom; each of Y 1  and Y 2  independently represents NRb (wherein Rb represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a heterocyclic group, an acyl group, an alkylsulfonyl group, or an arylsulfonyl group), a nitrogen atom, an oxygen atom, a sulfur atom, or a carbon atom; X 5  represents a group that can be bonded to Ma; “a” represents 1 or 2; R 8  and Y 1  may be linked to each other to form a 5-, 6-, or 7-membered ring; and R 9  and Y 2  may be linked to each other to form a 5-, 6-, or 7-membered ring. 
       
     
     
       7. The electrowetting display device according to  claim 6 , wherein at least one selected from the group consisting of R 2 , R 3 , R 4 , R 5 , R 8 , and R 9  in Formula (I-3) represents a linear or branched alkyl group having from 1 to 20carbon atoms. 
     
     
       8. The electrowetting display device according to  claim 6 , wherein X 5  in Formula (I-3) represents a group that neutralizes an electric charge of Ma, the group containing a linear or branched alkyl group having from 1 to 20 carbon atoms. 
     
     
       9. The electrowetting display device according to  claim 6 , wherein X 5  in Formula (I-3) represents a linear or branched alkyl ester group having from 1 to 20 carbon atoms. 
     
     
       10. A colored composition for use in electrowetting displays, the colored composition comprising:
 a dipyrromethene dye having a solubility in n-hexane of 1% by mass or higher at 25° C. and 0.1 MPa, the dipyrromethene dye being at least one compound selected from the group consisting of the following (a-1) to (a-7):